Filter assembly

ABSTRACT

A filter assembly for filtering fluid returning to a reservoir including a filter housing, a base closing one end of the housing, an outlet port in the base, and a perforated fluiddiffusing member enclosing said base together with the housing in an axially stacked arrangement therewith to disperse the discharge of fluid from the outlet port in a relatively wide flow pattern in order to minimize surface turbulence and resultant aeration of the fluid within the reservoir.

United States Patent [191 Rinaldo 1 Aug. 7, 1973 [54] FILTER ASSEMBLY[75] Inventor: James D. Rinaldo, Joliet, 111.

[73] Assignee: Caterpillar Tractor Co., Peoria, 111.

[22] Filed: Sept. 13, 1971 [21] App]. No.: 179,658

[52] US. Cl. 210/172, 210/451 [51] Int. Cl E031) 11/00, 801d 27/08 [58]Field of Search 210/451, 437, 456, I

210/137, 132, 247, 307, 441, 445, 429, 172, 167, DIG. 14

[56] References Cited UNITED STATES PATENTS 6/1966 Hultgren 210/D1G. 1711/1967 Niebergall 210/D1G. 17 9/1966 Humbert, Jr 210/D1G. 17

960,418 6/1910 Sclg 210/247 1,609,856 12/1926 Blackman 210/451 3,572,5083/1971 Rice 210/172 X Primary Examiner-Samih N. Zaharna AssistantExaminer-T. A. Granger Attorney-Fryer et al.

57 ABSTRACT A filter assembly for filtering fluid returning to areservoir including a filter housing, a base closing one end of thehousing, an outlet port in the base, and a perforated fluid-diffusingmember enclosing said base together with the housing in an axiallystacked arrangement therewith to disperse the discharge of fluid fromthe outlet port in a relatively wide flow pattern in order to minimizesurface turbulence and resultant aeration of the fluid within thereservoir.

9 Claims, 2 Drawing Figures PMENIEW INVENTOR JAMES D RINALDO I Y z aTTORNEYS s a a 00 m J m M v 3 r FILTER ASSEMBLY BACKGROUND OF THEINVENTION Hydraulic circuits normally include a filter assembly in thefluid return line to remove contaminants from the fluid as it is beingcirculated by the pump. A diffusing device is usually attached to thebottom or discharge end of the filter assembly to diffuse the flow offluid therefrom to minimize surface turbulence of the fluid in thereservoir and thereby reduce the resultant aeration of the fluid. Suchaeration can cause valve chatter and instability in the hydrauliccircuit. Often times, the filter assembly and diffusing device aremounted inside the reservoir of a hydraulic control system on a vehicleto reduce external piping, to protect the components from physicaldamage, and to conserve space on the vehicle.

Conventionally, the diffusing device comprises a perforated tube-likemember of uniform cross-section that is secured to the bottom of thefilter assembly by a flange and bolt arrangement, and it has its axispositioned perpendicular to the longitudinal axis of the filterassembly.

The bottom of the filter assembly and the diffusing device are usuallymade from metal castings which are complex and costly to manufacture.

SUMMARY OF THE INVENTION The present invention provides a compact,noncomplex, inexpensive and efficient filter assembly which includes aperforated fluid diffusing means for substantially minimizing fluidturbulence and resultant aeration. I

The filter assembly further comprises a housing having one end throughwhich fluid is discharged from the housing, a base member disposed inthe end of the housing, an outlet port formed in the base and diffusingmeans enclosing the end of the housing. The diffusing means comprises aperforated frustoconical member, axially aligned with the housing andbase, and enclosing the outlet port in the base to disperse fluiddischarged from the outlet port in a relatively wide flow pattern.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectional view of animproved filter assembly shown mounted in'a hydraulic reservoir.

FIG. 2 is a bottom view of the improved filter assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, afilter assembly 10. is shown in FIG. 1 as being mounted in a hydraulicreservoir or tank 12. The filter assembly includes a cylindrical housing14, a conically shaped base 16, a cartridgetype filter element 18 seatedon the base, an outlet port 20 formed through the base and positionedinteriorly of the filter element and a diffusing means or member 22. Theassembly is held together by means of a nut 24 welded to the diffusingmember, a cover 26, a coil spring 28 disposed between the cover and thefilter element and a tie-bolt 30 which threadably engages the nut.

The housing is provided with an inlet port 32 which directs fluid, beingreturned from a remote control system, into the filter assembly. Thefluid passes through the filter element, into interior chamber 34thereof and out through outlet port 20 and the diffusing member to thetank.

A bypass valve 38 is reciprocally mounted on the tiebolt at one end ofthe filter element. Should the element become clogged, the resulting lowpressure differential across the valve will allow the valve to openagainst a spring 40 to allow the return fluid to bypass the elementuntil the element is replaced.

The diffusing member has an annular flange 42 enclosing the base and thedischarge end of the housing, and defines a frustoconical chamber 44into which fluid is discharged from the outlet port. Alternately, theannular flange 42 may enclose the base 16 but be positionedlongitudinally inside the discharge end of the housing 14.

The housing and diffusing member are secured together such as bywelding, as shown at 46, or any other suitable means such as a bolt andflange arrangement. In this manner, the housing, base, and diffusingmember form an axially aligned unit which requires a mini- 'mum of spacein the hydraulic reservoir 12. Both the base and the diffusing memberare stamped from a flat sheet of material which affords an inexpensivemethod of manufacturing these parts.

The diffusing member is provided with a plurality of apertures 48 toallow fluid to escape from chamber 44. The apertures in the diffusingmember will spread out the flow of returning fluid so as to decrease thevelocity of the returning fluid. This will minimize the amount ofsurface turbulence of the fluid and as a result will mini mize aerationof the fluid in the reservoir.

I claim:

1. A cartridge-type filter assembly comprising a longitudinal tubularhousing, having a top end and a discharge end, a fluid inlet into saidtubular housing near the top end thereof,

the discharge end of said housing extending into a reservoir;

a base within said tubular housing disposed at the discharge end of saidhousing;

a fluid outlet port formed in said base, a filter element within saidhousing disposed between said fluid inlet and said fluid outlet, and aperforated frustoconical shaped fluid-diffusing means having a pluralityof apertures formed therein and enclosing said base in cooperation withsaid housing to communicate and disperse fluid discharged from theoutlet port in said base in a relatively wide flow pattern directly intosaid reservoir.

2. The filter assembly of claim 1 wherein said perforated diffusingmeans, said base and said filter housing form an axially aligned unit.

3. The filter assembly of claim 1 wherein the base is a generallyfrustoconical member having an upper smaller end and a larger lower end,and has an annular flange at the larger end thereof which abuts the dis-6. The filter assembly of claim 5 wherein said flange is welded to saidhousing.

7. The filter assembly of claim 5 further comprising a tie-boltextending therethrough along the axis 8. The invention defined in claim7 wherein said nut is secured to said diffusing member.

9 The invention of claim 4 further comprising a tubuthereof, and a nutabutting said diffusing member and 5 lat filter cartridge Seated on theannular

1. A cartridge-type filter assembly comprising a longitudinal tubular housing, having a top end and a discharge end, a fluid inlet into said tubular housing near the top end thereof, the discharge end of said housing extending into a reservoir; a base within said tubular housing disposed at the discharge end of said housing; a fluid outlet port formed in said base, a filter element within said housing disposed between said fluid inlet and said fluid outlet, and a perforated frustoconical shaped fluid-diffusing means having a plurality of apertures formed therein and enclosing said base in cooperation with said housing to communicate and disperse fluid discharged from the outlet port in said base in a relatively wide flow pattern directly into said reservoir.
 2. The filter assembly of claim 1 wherein said perforated diffusing means, said base and said filter housing form an axially aligned unit.
 3. The filter assembly of claim 1 wherein the base is a generally frustoconical member having an upper smaller end and a larger lower end, and has an annular flange at the larger end thereof which abuts the discharge end of the housing.
 4. The invention defined in claim 3 wherein said frustoconical member has an annular flat formed in the side thereof to provide a seat for an annular filter cartridge, and wherein said outlet port is formed in the smaller end thereof.
 5. The filter assembly of claim 1 wherein said perforated diffusing member includes an annular flange which abuts the base and extends circumferentially of the housing at the discharge end thereof.
 6. The filter assembly of claim 5 wherein said flange is welded to said housing.
 7. The filter assembly of claim 5 further comprising a tie-bolt extending therethrough along the axis thereof, and a nut abutting said diffusing member and threadably engaging said tie-bolt.
 8. The invention defined in claim 7 wherein said nut is secured to said diffusing member. 9 The invention of claim 4 further comprising a tubular filter cartridge seated on the annular flat. 